VARIETY INFORMATION:

For natural prasiolite mineral specimens see our For Sale or Sold lists

Prasiolite
(or vermarine) is the name for any quartz crystal or cluster that is green in color.
Although often cut as a gemstone, prasiolite is actually quite rare in nature.

Most prasiolites on the market are heat treated amethyst.
These stones are sometimes called "Green Amethyst", possibly because
amethyst is the starting variety, or possibly just because it sounds
more valuable that way. When heat treated, the amethyst from most locations transforms into yellow or orange citrine. From a few locations, a green color results.
These locations include Montezuma, Brazil, and Arizona. Naturally occurring
prasiolite has been reported from Poland.

Prasiolite (sometimes spelled
praziolite) can be confused with the similarly colored praseolite which
results from the heat treatment of iolite,
a variety of cordierite.
Note the spellings: prasioliteis the quartz variety, while praseolite
is the cordierite variety - not the other way around (which would be easier
to remember).

Note that prasiolite is macro-crystalline quartz. A green cryptocrystalline quartz, where the individual crystals are too small to be seen and the resulting transparency is translucent, would be called
chrysoprase.
The term prase is sometimes used for any leek-green color of quartz, whether
macro- or cryptocrystalline.

Some colorless quartz crystals have sufficient inclusions of chlorite to
result in a green color. However, this would not be considered prasiolite.
In any event, the color is wrong - more of a dark grass-green than a leek-green.
Note that green ghost crystals inside a clear quartz crystal is almost
certainly a chlorite coating over an earlier quartz crystal, and not an
example of quartz over prasiolite.

Prasiolite is only one of several quartz varieties.
Other varieties that form macroscopic (large enough to see) crystals are as follows: